A year ago, the conventional wisdom in baseball offices was that the Red Sox had the kind of starting pitching and overall pitching depth that should be envied, that the Rays' trade for Matt Joyce was one of the best trades of the winter, and that the Tigers were a mess and couldn't possibly compete in 2009.

There was some conventional wisdom that turned out to be right, of course. Yes, the Yankees were a lot better. The Brewers did, in fact, struggle to replace the production of CC Sabathia and Ben Sheets. And Stephen Strasburg did, in fact, back up his preseason standing as the best pitching prospect in the majors.

Here are eight bits of conventional wisdom about the season to come:

The Mariners have had the best offseason of any team.

They've signed Chone Figgins away from the Angels. They made what is widely seen as a great talent-for-talent trade for Cliff Lee. Their defense could be the best in the majors. All of that is absolutely true.

The addition of Cliff Lee means the Mariners will have two of the top Cy Young contenders pitching back to back. Getty Images

But it'll be interesting to see exactly how good the Mariners are, because their statistics from 2009 suggest that their great strides were improbable. They scored fewer runs than in 2008 but won 21 more games.

Russell Branyan had a tremendous first half, getting huge hits in big spots, and he will not be back. David Aardsma had an excellent season at closer, racking up the first 38 saves in his career; there will be questions about whether he can do it again. While the front end of their rotation is extraordinary, the makeup of the back end is kind of murky: Ryan Rowland-Smith, Ian Snell and Doug Fister are among the candidates.

A numbers-oriented friend recently ran a 1,000-season simulation of the AL West, and in most cases, the Rangers won the division, and in most cases, the last-place team was the Mariners. How good are the Mariners, actually? We'll see. Rob Neyer touched on this the other day.

The Yankees have the best chance for repeating as champions since the dynasty Yankees.